s = "朝千两轻辞里岸舟白江猿已帝陵声过彩一啼万云日不重间还住山，。，。"
b = ""
for i in range(4):
    b += s[i::4]
m = list(b)
print(m)

mylist = ['1', '2', '3', '4', '5'] 
s = '#'.join(mylist) #与split的区别
print(s)

mylist1 = [1, 'hello', '3', 'codemao'] 
mylist1.reverse()#逆向排序
print(mylist1)

str1 = {1,3,"codemao",7,3,3}#集合，无序，不重复,集合出现重复的值，不会报错，会被覆盖
print(str1)
a1 = [1, 3, "codemao", 7, 3, 3]
b1 = list(set(a1))#去重，转成集合
print(b1)

#创建空集合必须使用set（）,不能用{ }
sr = set()


